Add live transcript auto-save to .agents/transcripts/

[ElleNajt]

This PR implements automatic transcript saving that captures complete conversation history for archival purposes.

Features

Auto-saves transcripts as conversations progress:

• User prompts with timestamps
• Agent responses (streamed in real-time)
• Tool calls with status, commands, and output

Enabled by default - transcripts save to .agents/transcripts/{timestamp}.txt

Note on format: Transcripts are optimized for human readability (timestamped, formatted text). [Edit: This next sentence is wrong - ACP does support restoring sessions] While ACP doesn't currently support restoring sessions, a future enhancement could add a parallel machine-readable format for session restoration.

Configurable:

;; Disable if desired
(setq agent-shell-auto-save-transcript nil)

;; Change directory
(setq agent-shell-transcript-directory ".my-transcripts")

;; Customize filename generation
(setq agent-shell-transcript-filename-function
      (lambda () (format "chat-%s.txt" (format-time-string "%Y%m%d"))))

Relationship to shell-maker

This is separate from shell-maker's manual save functionality:

• shell-maker: Manual save on-demand or prompted save-on-close
• This feature: Automatic background archival to project directory

Users can use both, either, or neither depending on their needs.

Example transcript format

Agent Shell Transcript
Started: 2025-10-24 18:00:00
Working Directory: /Users/elle/code/agent-shell

============================================================

[2025-10-24 18:00:05] USER:
list files

[2025-10-24 18:00:06] AGENT:
I'll list the files in the current directory.

[2025-10-24 18:00:07] TOOL CALL [completed]:
  Tool: bash - Execute bash command
  Title: List files
  Command: ls -la
  Output:
total 256
drwxr-xr-x  15 elle  staff   480 Oct 24 18:00 .
...

Closes #63 - Auto-save transcripts without prompting

[ElleNajt]

Another benefit of doing something like this is that the buffers start to get laggy around 1M, and I'd like to have something like

(add-hook 'agent-shell-mode-hook
          (lambda ()
            (setq-local comint-buffer-maximum-size 50000)
            (add-hook 'comint-output-filter-functions 'comint-truncate-buffer nil t)))

In my personal config to keep the buffers manageable, and be able to look up the history if desired.

Perhaps I should open the that as a separate issue though.

[xenodium]

Thanks for the PR. Sorry, not had a chance to review. May need a little time...

Another benefit of doing something like this is that the buffers start to get laggy around 1M, and I'd like to have something like

1M characters? Something else? Could you please file a bug about this with more details? Bonus points if you investigate your laggy case. I spent some time recently chasing optimizations after a friend mentioned laggy buffers for codex agent. These helped, but I'm sure we can optimize elsewhere.

• 01b17aa
• f159739

Also, when reproducing the laggy scenario, make sure you update to the latest acp.el and logging is turned off (including saving any traffic), via M-x agent-shell-toggle-logging. Older acp.el versions saved traffic regardless.

Btw, you prolly already know this (and not a solution), but the "clear" command wipes the content of the buffer but doesn't wipe agent history.

Also, the markdown-overlay implementation is super expensive, specially for code blocks. If you comment out all of the (markdown-overlays-put), does your buffer still get laggy at 1M?

[ElleNajt]

1M characters, yes.

Btw, you prolly already know this (and not a solution), but the "clear" command wipes the content of the buffer but doesn't wipe agent history.

Ah, I didn't know this. I thought it was like /clear in claude, which does clear the agents context window. tbh, probably clear should mean to clear the context window ? I don't see a method in ACP for this though.

Could you please file a bug about this with more details?
Yes!

btw, looked more at ACP, and it does support restoring sessions: https://agentclientprotocol.com/protocol/session-setup#loading-sessions

[xenodium]

Ah, I didn't know this. I thought it was like /clear in claude, which does clear the agents context window. tbh, probably clear should mean to clear the context window ? I don't see a method in ACP for this though.

We're getting the "clear" command from "shell-maker" which merely clears shell content. I'm in two minds about also making it clear the agent. The convention seems to be that / is needed to operate on agent, though I can see how what we have today is confusing.

btw, looked more at ACP, and it does support restoring sessions: https://agentclientprotocol.com/protocol/session-setup#loading-sessions

While it's in the protocol, not all agents seem to support it. I've added a display of agent capabilities to surface these details more prominently

[xenodium]

Thanks for the PR. Here are some initial comments to get things going...

[xenodium]

Before opening the feature up for customizations, I'd like to give it some time to settle. This gives us time to use it, get a feel for it, and tweak without necessarily breaking users (if we decide to change settings around). Also gives us an opportunity to figure out how to reconcile this feature with the transcript feature in shell-maker (we need to turn that off, for example).

I'd say let's drop agent-shell-auto-save-transcript (we default to autosave) and agent-shell-transcript-directory for now. Let's rename agent-shell-transcript-filename-function to agent-shell--transcript-file-path-function (also private defvar).

For now if anyone would like to disable things, set agent-shell--transcript-file-path-function to nil.

This private var/function can take care of not just creating the file name but the entire path to write to.

[xenodium]

For now if anyone would like to disable things, set agent-shell--transcript-file-path-function to nil.

On second thought, can we make this nil by default and create an internal function we can set it to for the time being? This gives us the opportunity to override ourselves and use it for a bit of time before we roll it out to others.

[ElleNajt]

Makes sense to me!

[xenodium]

Example transcript format

Not for this PR, but we should consider iterating on log format later on. For example, we can maybe consider saving as .md. An upside is that opening in Emacs itself automatically gives us the ability to collapse and expand bits.

[ElleNajt]

Thanks for the feedback. Made the changes. Also, since it was a quick change, swapped from .txt to .md. Agreed that it makes sense to iterate on the log format.

[xenodium]

Thank you for the changes. LGTM, though looks like it needs to update to the latest to resove conflicts.

Added some minor comments. Mind addressing those when you resolve the conflicts?

[xenodium]

Hi @ElleNajt I got notification of some commits addressing comments. Thank you! Are you finished with the changes? If so, I'll look into merging.

[ElleNajt]

Hi -- yes, finished with the changes! :)